耕翻干扰对丰宁坝上孤石牧场种子库及地上植被的影响

The impact of cultivation disturbance on the seed bank and aboveground vegetation of the pasture on Fengning Bashang Gushi grazing farm

主要论述了在3种恢复方式下即自然恢复（对照）、浅耕（10 cm）、深耕（20 cm）下地下种子库和地上植被在物种组成、种子数量、物种多样性以及种子垂直分布方面的变化规律和二者之间的相关性.结果表明,在浅耕处理下,无论是地上还是地下多样性均有所增加,较好地促进了种子的萌发,但生物量有所下降,究其原因可能是人为的耕翻干扰增加了一、二年生草本植物所占比例的缘故;不同恢复方式对种子数量的垂直分布也有很大影响,自然恢复与一般规律相似,有78.5%的种子分布在0～10 cm,而浅耕和深耕处理分别有75.4%和54.1%分布在0～10 cm;该退耕地还处于演替的初期,土壤种子库与地上植被有一定程度的相关性.

The variation rules and relationships between the soil seed bank and the aboveground vegetation in species composition, amount of seeds, species diversity and vertical distribution of seeds were studied under three restoration forms in this paper. The results showed that the species diversity increased whether in the soil or aboveground with lower cultivation, which better improved seeds growth. But the amount of the biomass decreased, the reason might be that the proportion of annual, biannual plants was increased by artificial cultivation disturbance. There was a further influence with different restoration forms on the vertical distribution of seeds, and the rules of natural restoration were just same as general, i.e. 78.5% seeds distributed in the soil horizon of 0-10 cm, while there were 75.4% and 54.1% distributing in the soil horizon of 0-10 cm under lower and deeper cultivation. This returned farmland was still at the initial succession stage, and there was a closed relationship between the soil seed bank and aboveground vegetation.